A combine harvester is a machine that is used to harvest grain crops. The objective is to complete several processes, which traditionally were distinct, in one pass of the machine over a particular part of the field. Among the grain crops that may be harvested with a combine are wheat, oats, rye, barley, corn, soybeans, flax or linseed, and others. The waste (e.g., material other than grain (MOG)) discharged on the field includes the remaining dried stems and leaves of the crop which may be, for example, chopped and spread on the field as residue or baled for feed and bedding for livestock.
A combine harvester cuts crop using a wide cutting header. The cut crop may be picked up and fed into the threshing and separating mechanism of the combine, typically consisting of a rotating threshing rotor or cylinder to which grooved steel bars commonly referred to as rasp bars or threshing elements may be bolted. These rasp bars thresh and aid in separating the grains from the MOG through the action of the rotor against a cylindrical threshing chamber.
In an axial flow combine, this threshing and separating system serves a primary separation function. The harvested crop is threshed and separated as it is conveyed between a longitudinally arranged rotor and the inner surface of the cylindrical chamber. The cut crop material, or crop mat, spirals and is conveyed along a helical path within the chamber until substantially only larger residue remains. When the residue reaches the end of the threshing drum, it is expelled out of the rear of the combine via a spreader mechanism. Meanwhile, the grain, chaff, and other small debris fall through openings in the threshing chamber onto a cleaning device or shoe, where the grain is further separated from the chaff by way of a winnowing process.
The lower portion or bottom 180 degrees of the cylindrical chamber comprises threshing and separating concaves that may be fitted with steel bars and a meshed grill, through which grain, chaff and smaller debris may fall, whereas the straw, being too big or long, is carried through to the outlet. The upper portion or top 180 degrees of the cylindrical chamber comprises cages that may be fitted with vanes which also aid in separating the grains from the MOG. The dimensions (e.g. length, thickness, angle, etc.) of the vanes control the speed of the crop material conveyed through the chamber, influencing the function of the rotor.
Some conventional cage vanes include fixed helical shaped C-Channels and fixed flat plates. Due to the desire to adjust the performance of the combine to meet varying crop conditions, other conventional vane approaches include L-angle iron vanes which are manually adjustable. The adjustable L-angle iron vanes are constructed of structural angle iron. While the L-angle iron vanes provide some functionality and stability, each leg of the L-angle iron vanes are of constant length and thickness as the legs extend from one edge of the vane to the other edge of the vane. These dimensions and the inherent strength of the structural angle iron vanes make it very difficult to manually adjust the vanes manually in the directions of desired distortion. Accordingly, what is needed is an improved cage vane and cage vane threshing system.